1. Field of the Invention
The present invention relates to a carrier conveying apparatus.
2. Description of the Prior Art
In a semiconductor heat-treating device, etc., a carrier conveying apparatus has been employed which conveys a carrier with a plurality of semiconductor wafers substantially vertically held in a spaced-apart relation.
An apparatus having a gripping means for gripping carriers from above is conventionally known as a carrier conveying apparatus. The carriers are conveyed by a gripping means-equipped carrier conveying apparatus as will be set out below. First, the gripping means is moved, by liftably moving means and horizontally moving means, to a desired height above the carrier. Then, the gripping means is opened at the desired position and lower toward the carrier. The gripping means, upon reaching a given position, stops its lowering and grips the carrier by closing the gripping means. The gripping means is moved in a lifting motion and in a horizontal motion with the carrier gripped thereby. The gripping means, upon reaching a desired position, releases the carrier with the gripping means opened and place the carrier in place.
In the case where the carrier is gripped and conveyed to the predetermined position, for example, dust, etc., is raised upon the opening and closing operate the gripping means from a sliding part of the gripping means, falling on the surfaces of wafers in the carrier. In this way, the dust is deposited there. As a result, drop in the yield of semiconductor devices, which are finished products, results.